With good lights, the reflector is practically if not legally redundant. IME lights that are also reflectors are nowhere near as bright as the Radbot 1000 or the PBSF. So, run one of the good lights, and ALSO run one of the reflector lights so you comply with the letter of the law, too.

Also, another good taillight in the OPs price range is the Cateye TL-LD1100. Not as bright as the PBSF from directly behind, but it has a much wider "beam pattern", if taillights can be said to have a "beam pattern". Also, it uses AA batteries instead of AAAs, so it also has a really good battery life.